calendar: exempt Vigils from Our Lady's Saturday's demotion

Refined per direct correction: Our Lady's Saturday is really only a
Simplex-strength standing, not a privileged-feria-minor-shaped one --
a Vigil keeps forcing its own primacy on a Saturday the same way it
already does any other day (see calendar/commemorations.ts's own
transferDirectionOf special-casing for Vigils elsewhere). Only a
Simplex saint alone now loses to it; a Vigil, along with anything
Semiduplex-or-higher, wins outright and Marian Saturday doesn't apply.

Un-does the two test-date moves this same regression prompted last
time (Vigil of St. Lawrence, Vigil of St. John Baptist) -- both dates'
original years work again now that the fix is right.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>

src/calendar/index.ts

@@ -140,13 +140,18 @@ function applyChristTheKing(isoDate: string, winner: DayWinner, commemorations:
 /**
  * Layered on top of everything above, same spirit as applyOctaves: never
  * changes decideOccurrence's own rules, just relabels the result on a free
- * Saturday. Real standing of its own (per direct instruction, mirrors
- * privileged-feria-minor exactly) — a Semiduplex-or-higher saint still
- * wins outright and this never applies; a Simplex (or Vigil) saint loses
- * to it and is commemorated instead, same as an Advent feria would demote
- * one. `ordinary-feria` is the only category this touches — every
- * privileged season/day (Ember Saturdays, Advent, Lent, ...) already has
- * its own real standing and keeps it untouched.
+ * Saturday. Real standing of its own, but only really a Simplex-strength
+ * one (per direct instruction, refined from an earlier "mirrors
+ * privileged-feria-minor exactly" pass that also swept in Vigils, which
+ * turned out wrong: a Vigil keeps forcing its own primacy on a Saturday
+ * the same way it already does any other day, same as Simplex always has
+ * — see calendar/commemorations.ts's own transferDirectionOf for Vigil's
+ * usual special standing elsewhere) — a Simplex saint alone loses to it
+ * and is commemorated instead; anything Semiduplex-or-higher, or a Vigil,
+ * still wins outright and this never applies. `ordinary-feria` is the
+ * only category this touches — every privileged season/day (Ember
+ * Saturdays, Advent, Lent, ...) already has its own real standing and
+ * keeps it untouched.
  *
  * The relabel (not just leaving `winner` as the plain temporal id) is
  * what lets getDayLabel/getBenedictusAntiphon/getDayCollects/getLaudsPsalmodyOverride
@@ -175,7 +180,7 @@ function applyMarianSaturday(
   if (winner.kind === 'temporal') {
     return MARIAN_SATURDAY;
   }
-  if (isAtLeast(winner.rank, 'semiduplex')) {
+  if (winner.rank !== 'simplex') {
     return winner;
   }
   commemorations.push({ kind: 'sanctoral', id: winner.id, name: winner.name, rank: winner.rank });

tests/calendar/august-sanctoral.test.ts

@@ -53,10 +53,7 @@ describe('August sanctoral pull (first pass)', () => {
   });
 
   it("the Vigil of St. Lawrence's own vigil rank forces primacy over a real, otherwise-unranked secondary saint", () => {
-    // 2025-08-09 is a Saturday -- collides with the generic Saturday-of-
-    // Mary votive this test isn't about (see tests/calendar/marian-
-    // saturday.test.ts); 2024 keeps it a plain midweek day.
-    const day = resolveDay('2024-08-09');
+    const day = resolveDay('2025-08-09');
     expect(day.winner).toEqual({
       kind: 'sanctoral',
       id: 'vigil-of-st-lawrence',

tests/calendar/june-sanctoral.test.ts

@@ -40,11 +40,8 @@ describe('June sanctoral pull (first pass)', () => {
   });
 
   it('the Nativity of St. John the Baptist wins outright at Duplex I. classis, distinct from his Vigil the day before', () => {
-    // 2035-06-23 is a Saturday -- collides with the generic Saturday-of-
-    // Mary votive this test isn't about (see tests/calendar/marian-
-    // saturday.test.ts); 2027 keeps both dates on plain midweek days.
-    const vigil = resolveDay('2027-06-23');
-    const nativity = resolveDay('2027-06-24');
+    const vigil = resolveDay('2035-06-23');
+    const nativity = resolveDay('2035-06-24');
     expect(vigil.winner).toEqual({
       kind: 'sanctoral',
       id: 'vigil-of-st-john-the-baptist',

tests/calendar/marian-saturday.test.ts

@@ -2,11 +2,11 @@ import { describe, expect, it } from 'vitest';
 import { resolveDay } from '../../src/calendar';
 import { getDayLabel } from '../../src/calendar/day-label';
 
-// Direct instruction: on a free Saturday, "Our Lady's Saturday" mirrors
-// privileged-feria-minor exactly — Semiduplex-or-higher still wins
-// outright (Marian Saturday doesn't happen); below that (Simplex, and
-// Vigil, since both are below semiduplex in the FeastClass scale), the
-// saint loses and is commemorated instead.
+// Direct instruction: on a free Saturday, "Our Lady's Saturday" is really
+// only a Simplex-strength standing — a Simplex saint alone loses to it
+// and is commemorated instead; anything Semiduplex-or-higher, or a Vigil
+// (which keeps forcing its own primacy the same way it does any other
+// day), still wins outright and Marian Saturday doesn't apply at all.
 describe('Marian Saturday (applyMarianSaturday)', () => {
   it('wins outright, with no commemoration, on a Saturday with nothing else at all going on', () => {
     const day = resolveDay('2026-10-24');
@@ -23,12 +23,21 @@ describe('Marian Saturday (applyMarianSaturday)', () => {
     ]);
   });
 
-  it('wins over a Vigil too (below semiduplex, same as Simplex) -- can commemorate more than one loser at once', () => {
-    const day = resolveDay('2025-11-29'); // St. Saturninus (Simplex) + Vigil of St. Andrew
-    expect(day.winner).toEqual({ kind: 'temporal', id: 'marian-saturday' });
+  it('loses to a Vigil, which keeps forcing its own primacy on a Saturday same as any other day -- Marian Saturday does not apply', () => {
+    // 2025-11-29: Vigil of St. Andrew collides with St. Saturninus
+    // (Simplex) via calendar/collision.ts (Vigil outranks Simplex there)
+    // before Marian Saturday even gets a look-in -- Vigil wins outright,
+    // Saturninus is commemorated as the collision's loser, not by Marian
+    // Saturday's own demotion rule.
+    const day = resolveDay('2025-11-29');
+    expect(day.winner).toEqual({
+      kind: 'sanctoral',
+      id: 'vigil-of-st-andrew',
+      name: 'Vigil of St. Andrew',
+      rank: 'vigil',
+    });
     expect(day.commemorations).toEqual([
       { kind: 'sanctoral', id: 'st-saturninus', name: 'St. Saturninus, Martyr', rank: 'simplex' },
-      { kind: 'sanctoral', id: 'vigil-of-st-andrew', name: 'Vigil of St. Andrew', rank: 'vigil' },
     ]);
   });